Safety device for point-switches



L. DUNN.

SAFETY DEVICE FOR POI'NT SWITCHES. APPLICMVION FILED SEPT. 26, 191.9.

Patented Apr. 13, 1920. n N m 3 SHEETS-SHEET 1. i

FIG-ll L. DUNN.

SAFETY DEVICE FOR POINT SWITCHES. APPLIQMIQN FILED SEPT-26, 1919.

Patented Apr. 1%?

3 SHEETS-SHEET'Z.

, L. DUNN. SAFETY DEVICE FOR POINT SWITCHES.

APPLICATION FILED SEPT-26, I919- 1,337,054. Patented Apr. 13, 1920.

3 SHEETS-SHEET 3- //v VENTOR Lou/s Du/v/v UNITED STATES PATENT OFFICE.

LOUIS DUNN, OF ST. PAUL, MINNESOTA, ASSIGNOR TO EDMUND L. DUNN, OF ST. PAUL, MINNESOTA.

SAFETY DEVICE FOR POINT-SWITCHES.

' Specification of Letters latent.

Patented Apr. 13, 1920.

To all whom it may concern:

Be it known that I, LOUIS DUNN, a citizen of the United States, resident of St. Paul, county of Ramsey, State of Minnesota, have invented certain new and useful Improvements in Safety Devices for Point-Switches, of which the following is a specification.

The object of my invention is to provide a means to cooperate with the safety device shown and described in Letters Patent of the United States, No. 867,709, issued to me October 8, 1907, to the end that when a train is passing on to a siding from the main line it will be impossible for the switch point to accidentally or prematurely move or shift until the last truck of the train has passed over the points, and thereby all danger of derailing the train or a portion of it through the premature movement of the switch will be entirely eliminated.

Other objects of the invention will appear from the following detailed description.

Inthe accompanying drawings forming part of this specification,

Figure 1 is aplan view of a section of a railroad track and a point switch and operating mechanism therefor,

Fig. 2 is a view of the switch stand,

Fig. 3 is a sectional view on the line 3-3 of Fig. 1,

Fig. 4 is a sectional view on the line 4.l of Fig. 1, showing the safety bar in its lowered position,

Fig. 5 is a similar view, showing the bar raised to a point where it will be struck by the wheels of the train,

Fig. 6 is a similar view, showing thebar depressed by the pressure of the wheels.

Fig. 7 is a sectional view on the line 7--7 of Fig. 1, i I

Fig. 8 is a sectional view on the line 8-8 p of Fig. 4,

Fig. 9 is a sectional view on the line 99 of Fig. 6, r

Fig. 10 is a sectional view on the line 1010.of.Fig. 1. v In the drawing, 2 and 3 represent the rails ofthe main track and 4 and 5 the rails of the side track. 6 and 7 are the switch points for directing the train from the main to the side track. A rod 8 connects the points for simultaneous movement and a spring device 9 normally tends to hold the points away from the main rail 2 and against the stop device 10. .A switch stand 11 is mounted on a base 12 at one side of the track and is provided with a lever 13 mounted to swing vertically and enter notches provided in the top of the stand for locking the switch in its different positions. At one end of its stroke the lever drops into one notch for locking the switch for the main line and at the other end of its movement it drops into another slot when the switch is set for the siding and between these two points there is no intermediate or neutral position in which the points are withdrawn from con tact with both rails. A link 15 connects the switch stand with an arm 16 mounted on a rock shaft 17 having horizontal'bearings 18 at one side of the track. This arm is made adjustable on the rock shaft for the purpose of obtaining the desired degree of stroke of the shaft. When the switch stand is operated by means of the lever 18, the link 15 will transmit movement of the stand to the rock shaft 17 An arm 19 connects the rock shaft with the rod 8 for shifting the switch points back and forth with the movement of the switch stand. Crank arms 20 are also mounted on the rock shaft and rods 21 have threaded engagement with these crank arms for adjustment longitudinally therein. The rods 21 have tapered ends 22 which are mounted to slide in guides 23 provided on the underside of the track rails. A bar 24: has-slots 25 to receive the tapered ends of the rods 21, the points of the rods normally fitting within the slots 25 and resting in the guides 23 and supporting the bar 24 in its depressed position, as shown in Fig. 4:. When, however, the rods are moved longitudinally by the rocking of the shaft 17 the beveled ends of the rods 21 being thrust through the slots 25 and engaging the upper wallsof said slots, will raise the bar 24 to the position shown in Fig. 5 where the upper edge of the bar will be slightly above the track rail and will contact with the tread of the wheel and be depressed thereby so that the rods 21 will be locked in the slots .25 and cannot be moved or the switch stand operated until the pressure on these rods has been relieved by the passage of the train over the bar. It will thereby be impossible to operate the shaft 17 and move the switch points 6 and 7 until the train has entirely passed over the points.

To assist in withdrawing the tapered or beveled rods from their working engagement with the safety bar, I provide an arm 26 on the rock shaft 27 adapted to swing down to a horizontal position beneath a weighted arm 27. This arm has freedom of movement vertically for a limited distance, as indicated in Fig. 7, but on the latter part of the stroke of the rods 21 this weighted arm 27 will be lifted and the weight thereon will assist in the initial backward movement of the rods 21 after the passage of the train.

For the purpose of automatically disengaging the locking lever 13 and swinging it to its horizontal, releasing position, I provide a bar 28 mounted to slide transversely of the track rails 4 and 5 and having plates 29 and 30 thereon in the path of the wheel flanges to be actuated thereby. A bell, crank 31 is pivotally connected with the bar 28 and with a rod 32 which extends to a second bell crank 33 from which a cross rod 34 extends to a bell-crank 35 having a pivotal connection 36 with a 'lever37 pivoted at 38 on .the switch stand and having'an arm39 mounted to project between the stand and .the locking lever 13 for the purpose of disengaging said lever from its notch in the switch stand when automatic operation of the switch is desired toset the switch for the siding.

1. The combination, with the main line track rails, of the movable switch points, a switch lever operatively connected with said switch points, mechanism for automatically throwing the switchpointsto a neutral position whenthe train passes onto the siding, a bar mounted for vertical movement into the path of the truck wheels, and mechanism locked by the'pressurezof the truck wheels on said bar .to prevent movement of the switch points until the last truck has passed from the main trackrailsito the siding.

2. The combination, with the main line track rails, of the movable switch points, a switch \leveroperatively connected with said switch points,.mechanism for automatically throwingthe switch points to a neutral position when the train passes onto the .--siding, a vertically movable .bar having an opening therein, and a :tapered member slidable in said opening for raising :-said bar into contact with the truck wheels, said tapered member being connected with the switch points and being locked by the pressure of the truck wheels on said bar.

3. The combination, with the main line track rails, of the movable switch points, a switch lever operativelyconnectedwith said switch points, mechanism for automatically throwing the switch points to a neutral position when the train passes onto the siding, a reciprocating bar connected with said lever and means raised by the movement of said bar in one direction to contact with the truck wheels, the pressure 'of the wheels on said means locking said bar against movement in either direction. l

4. The combination, with the main line track rails, of the movable switch points, a switch lever operatively connected with said switch points, mechanism for automatically throwing the switch points to a neutral position when the train passes onto the siding, a reciprocating bar connected with said switch lever and provided with a tapered ,end, a plate having a slot therein to receive said tapered end, a guide whereonsaid bar is horizontally movable, said bar operating to raise said plate into the path of the truck wheels, the pressure of the wheelson said plate locking said bar on said guide and in the slot in said plate.

5. The combination, with the main line track rails, of the movable switch points, a switch lever operatively connected with said switch points, mechanism for automatically throwing theswitch points to a neutral position whenthe train passes onto the siding, a vertically movable safetyiba-r, rods connected with said switch lever and mounted to. engage and "elevate said bar into the path of the truck wheels, pressure of the wheels on said bar temporarily locking said rods and preventing premature movement of the switch, and a weight device for aiding the withdrawal of said rods .from said safety bar when the truck wheels have passed the switch.

6. The combination, with the main .line track rails, of the movable switch points, a switch lever operatively connected with said switch points, mechanism for automatically throwing the. switch points to a neutral'position when the train passes .onto the siding, a safety bar mounted to be moved .into .the path of ,the truck wheels, means connected with said switch lever for operating said bar, and a weight device mountedto aid in the withdrawal of said bar operating means when atruck has passed out of contact with said bar.

7. The combination, with the mainline track rails, of the movable switch points,,a switchlever operatively connectedwith said switch points, mechanism for automatically truck wheels have passed out of contact with throwing the switch points to a neutral posisaid bar. tion when the train passes onto the siding, a In Witness whereof I have hereunto set my rock shaft, a safety bar, rods connected with hand this 5" day of September, 1919.

5 said shaft and engaging said bar for elehis Vating it into the path of the truck wheels, LOUIS X DUNN. an arm mounted on said rock shaft, and a mark weighted arm engaging said rock shaft arm Witnesses: to aid in the withdrawal of said rods from MARGARET DE EGLIsE,

10 engagement with said safety bar when the GENEVIEVE E. SoRENsEN. 

